Protection filter for hemodialysis lines

ABSTRACT

A protection filter for hemodialysis lines includes a body provided with conduit coupling members, a first conduit being connected to a dialysis machine and the second conduit being directed towards a patient. The coupling members present generally coaxial internal holes opening at their ends, the holes mutually communicating within the interior of the body, within the body a filter element is present disposed between the holes of the coupling members. The body of the filter is in one piece, is homogeneous and is without joining lines between its various parts. The body incorporates the end edges of the filter element.

The present invention relates to a protection filter for hemodialysislines in accordance with the introduction to the main claim.

A protection filter for hemodialysis lines is known to comprise a bodyconnected to two conduits, of which a first conduit is connected to adialysis machine and the second conduit is directed towards the patient.The body of known filters usually presents a normally discoidal centralportion having opposing faces from which usually cylindrical orfrusto-conical connection members project for connection to saidconduits. Each connection member or coupling is provided with a throughhole opening at the free end of the relative member and joined to theother hole within the central portion of the filter body. In thislatter, between the two holes a filter element is present generallydefined by an antibacterial, hydrophobic and hemophobic membrane—i.e. amedia filter system.

The purpose of this membrane is to enable air to be transferred from oneconduit to the other via a filter (blocking the blood) in order toenable, via this latter, the hemodialysis treatment to be controlledwhile being carried out on a patient and to preserve (or protect) thedialysis machine from possible contact with the blood. This control isin fact achieved by measuring the pressure of the hemodialysis line bypassage of the air passing through the filter, this air generating apressure in the conduit directed towards the dialysis machine, thispressure being measured by known usual sensor means positioned in thatconduit or in the machine. The filter element (membrane or other) henceenables air to pass while blocking blood flow towards the machine, thepatient dialysis process being controlled by means of this passage.

Known filters, of any form, present a body generally produced in two ormore parts welded together (for example by ultrasonic welding). Forexample a known filter comprises a body presenting two parts, eachprovided with a generally discoidal portion, from a face of which thereprojects a member for coupling or connecting to a relative conduit(tube). The filter is produced by coupling together the generallydiscoidal portions of the two parts after inserting a filter elementbetween them; the two coupled parts of the two portions are then weldedtogether, to define the filter body.

This known solution therefore presents an undeniable productioncomplexity, which reflects on the filter production costs.

Another known process for producing a protection filter for hemodialysislines comprises firstly moulding from plastic a part of the filter bodypresenting the discoidal portion and the coupling member, then openingthe mould to arrange the filter element on the discoidal portion andthen overmoulding the second part of the filter body provided with theother discoidal portion and the relative coupling member. This method ofproducing the filter for hemodialysis lines results in a non-homogeneousbody in which its two parts are separated and distinguishable from eachother. This solution is also laborious and costly.

Moreover as the known solutions comprise a plurality of operations to becarried out on the individual components of the filter body, theyinevitably lead to a non-negligible percentage of product defects, thisalso having to be considered in evaluating the final cost of thecorrectly finished product ready for sale. These defects can also beproblematic if they are not identified prior to marketing the filter inthat they can lead for example to blood passage through the filter andtowards the dialysis machine.

An object of the present invention is to provide a protection filter forhemodialysis lines which overcomes the drawbacks of the known solutionsand which represents an improvement thereon.

Another object is to provide a protection filter for hemodialysis linesof the aforestated type which is of simpler production than knownfilters and is hence of lower production cost then these.

A further object is to provide a filter of the aforestated type whichoffers considerable safety in use.

These and other objects which will be apparent to the expert of the artare attained by a protection filter for hemodialysis lines in accordancewith the accompanying claims.

The present invention will be more apparent from the accompanyingdrawing, which is provided by way of non-limiting example and in which:

FIG. 1 is a partly broken-away perspective view of a first embodiment ofthe invention; and

FIG. 2 is a perspective view similar to that of FIG. 1, but of adifferent embodiment of the invention.

With reference to said figures, a protection filter for hemodialysislines is indicated overall by 1 and presents a completely homogeneousone-piece body 2 with no joining lines or regions in its various parts.In the embodiments shown in the figures by way of non-limiting example,these parts comprise a substantially central discoidal portion 3 usefulfor “manipulating” the filter, and having two opposing flat faces 4 and5 with coupling members 7 and 8 projecting from said faces 4, 5. Thesemembers are arranged to cooperate with conduits or tubes directedtowards a patient subjected to dialysis and towards a dialysis machine.

The coupling members comprise a through hole 9, 10 respectively, openingat the free ends 7A, 8A of the corresponding member 7 and 8. The holes 9and 10 are for example (but not necessarily) coaxial and are connectedtogether at the discoidal portion 3 where they are separated by a filterelement 12.

The filter element 12 presents at least one end edge 13 incorporatedinto the one-piece body 2 so that it becomes securely fixed to thislatter. This element can be flat (FIG. 1) or of beak type with pleatedor folded walls or it can extend axially within the body 2 and presentsa plurality of surface pleats which increase the transfer surface. As analternative, the element 12 can be of hemispherical form similar to adome or have any other form able to define a large filtering surface forequal bulk.

The discoidal portion 3 can advantageously present a raised end edgerising peripherally from one of its faces 4, 5, said edge facilitatingmanipulation of the filter in connecting the body 2 to at least onecorresponding conduit.

The body 2 of the filter 1, produced by known plastic moulding, is ofvery small size. For example it has an axial height between 10 and 50 mmand a diameter between 4 and 20 mm. The portion 3 can have a diameterwhich depends mainly on its appearance and related to the positioning ofthe filter in the dialysis machine, and is between 4 and 50 mm. The bodyis produced by moulding in a single operation (method known asovermoulding or insert moulding) during which the members 7 and 8 andthe portion 3 are formed simultaneously, said elements being overmouldedsimultaneously on the filter is element 12, which is hence incorporatedand inserted into the body 2 of the filter 1.

The invention is hence of simple and rapid implementation. Being in onepiece and being without joining lines between its various components(the members 7, 8 and the portion 3), it is also of reliable use in thatits shape ensures lack of seepage and leakages in terms of blood andair. The body 2 of the filter 1 is produced in a single mouldingoperation and is hence of much lower complexity and costs than similarknown solutions.

A particular embodiment of the invention has been described. However thebody 2 of the filter 1 can also be of different shape than that shown inthe drawings; for example, it can be completely tubular, without thegenerally discoidal portion 3 (with flat faces or with a raisedperimetral edge), in which case the members 7 and 8 are defined by theends of the tubular body. In another embodiment, this body can beprismatic and provided with the members 7 and 8. In any event, whateverits shape this body is in one piece and without joining lines, it beingprovided with a through conduit defined by holes provided in thecoupling members 7 and 8 and mutually communicating via a filter elementin the body interior and with its lateral edge incorporated into saidfilter body.

These solutions are also to be considered as falling within the scope ofthe following claims.

1. A protection filter for hemodialysis lines comprising: a bodyprovided with conduit coupling members, a first conduit being connectedto a dialysis machine and the second conduit being directed towards apatient, said coupling members presenting internal holes opening attheir ends, said holes mutually communicating within the interior ofsaid body, within this body a filter element disposed between the holesof the coupling members, wherein the body of said filter is in onepiece, is homogeneous and is without joining lines between the variousparts of the body, said body incorporating end edges of the filterelement.
 2. A protection filter for hemodialysis lines as claimed inclaim 1, being of plastic material moulded in a single mouldingoperation.
 3. A protection filter for hemodialysis lines as claimed inclaim 2, wherein the moulding is an overmoulding or an insert moulding.4. A protection filter for hemodialysis lines as claimed in claim 1,wherein the filter element is flat.
 5. A protection filter forhemodialysis lines as claimed in claim 1, wherein a said internal holeof one said conduit coupling member is coaxial with a said internal holeof another said conduit coupling member, the filter element is axiallyelongated within the body along the interior of one of the coaxial holespresent in one of the coupling members of the body.
 6. A protectionfilter for hemodialysis lines as claimed in claim 5, wherein the filterelement has folded or pleated walls.
 7. A protection filter forhemodialysis lines as claimed in claim 5, wherein the filter element hasa hemispherical wall.
 8. A protection filter for hemodialysis lines asclaimed in claim 1, wherein the internal holes of the coupling membersare coaxial.
 9. A protection filter for hemodialysis lines as claimed inclaim 1, wherein the body is tubular, its opposing ends defining thecoupling members.
 10. A protection filter for hemodialysis lines asclaimed in claim 1, wherein the body is prismatic.
 11. A protectionfilter for hemodialysis lines as claimed in claim 1, wherein the bodypresents a substantially discoidal laterally projecting portion.
 12. Aprotection filter for hemodialysis lines as claimed in claim 11, whereinsaid portion comprises two opposing faces from which the couplingmembers project.
 13. A protection filter for hemodialysis lines asclaimed in claim 12, wherein one of the opposing faces of thesubstantially central portion presents a raised free edge.
 14. Aprotection filter for hemodialysis lines as claimed in claim 1, havingan axial height of between 10 and 50 mm and a diameter of between 4 and50 mm.
 15. A method for producing a protection filter for hemodialysislines claimed in claim 1, comprising a single moulding operationeffected with plastic material on a filter element inserted into amould, said single moulding operation resulting in a homogeneousone-piece body of the filter without joining lines between the variousparts of the body, said body incorporating the end edges of the filterelement.